Pessaries of Gentamicin Sulphate for the Treatment of Bacterial Vaginosis: Formulation Development

Abstract

Aim: To develop pessaries for the treatment of bacterial vaginosis. Vaginosis is a disease resulting from abnormal bacterial or fungal proliferation of the vagina, causing discomfort to the patient. There are numerous pessaries for the treatment of fungal vaginosis, but a paucity of such pessaries exists for bacterial vaginosis. Development of pessaries for the treatment of bacterial vaginosis therefore becomes pertinent. Study Design: In vitro and In vivo evaluation of the effectiveness of pessaries formulated for bacterial vaginosis. Place and Duration of Study: Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria; between May 2024 and February 2025. Methodology: The non-natural bacteria colonizing the vagina were isolated using standard methods and their susceptibility to gentamicin sulphate was tested to establish the effective inhibitory concentration. This concentration guided the formulation of different batches of the pessaries, which were evaluated using dissolution studies. The pessaries with the optimal inhibitory concentration were formulated to suite rat’s vagina. The effectiveness of treating vaginosis caused by bacteria using gentamicin sulphate pessaries in a rat model was investigated. Results: All the clinically isolated bacteria showed sensitivity to gentamicin sulphate at 0.4 mg/ml (P = .05).  A 4 % formulated pessary showed good release in vitro, and a 5-minute dissolution sink cleared all the isolated bacteria. A suitably formulated pessary reduced Staphylococcus aureus load in a rat-infected model by 97.5 % and Escherichia coli by 55.3 %. Conclusion: Gentamicin sulphate pessaries could be used to treat vaginosis caused by susceptible bacteria.